In the current study, sweet potato peel (Ipomoea batatas) was observed as the most favorable substrate for the maximum synthesis of α-1,4-glucosidase among various agro-industrial residues. Bacillus licheniformis KIBGE-IB4 produced 6533.0 U ml⁻¹ of α-1,4-glucosidase when growth medium was supplemented with 1% dried and crushed sweet potato peel. It was evident from the results that bacterial isolate secreted 6539.0 U ml⁻¹ of α-1,4-glucosidase in the presence of 0.4% peptone and meat extract with 0.1% yeast extract. B. licheniformis KIBGE-IB4 released 6739.0 and 7190.0 U ml⁻¹ of enzyme at 40 °C and pH 7.0, respectively. An improved and cost-effective growth medium design resulted 8590.0 U ml⁻¹ of α-1,4-glucosidase with 1.3-fold increase as compared to initial amount from B. licheniformis KIBGE-IB4. This enzyme can be used to fulfill the accelerating demand of food and pharmaceutical industries. Further purification and immobilization of this enzyme can also enhance its utility for various commercial applications. Graphical abstract Pictorial representation of maltase production from sweet potato peel

Plastics are widely used in the production of short-life products, which are discarded producing an accumulation of these materials and problems due to their persistence in the environment and waste management systems. Degradable plastics (compostable, oxodegradable) have been presented as an alternative to decrease the negative effect of plastic waste. In this research, the feasibility of degrading a commercially available compostable film and oxodegradable polyethylene, with and without previous abiotic oxidation, is assessed in a home composting system. Reactors (200 L) were used to degrade the plastic films along with a mixture of organic food waste (50 %), mulch (25 %), and dry leaves (25 %), amended with yeast and a solution of brown sugar to increase the speed of the process. The presence of the plastic film did not affect the composting process, which showed an initial increase in temperature and typical profiles for moisture content, pH, with a final C/N of 17.4. After 57 days, the compostable plastic has decreased its mechanical properties in more than 90 %, while the oxodegradable film did not show significant degradation if it was not previously degraded by UV radiation. The use of these plastics should be assessed against the prevailing waste management system in each city or country. In the case of Mexico, which lacks the infrastructure for industrial composting, home composting could be an option to degrade compostable plastics along organic waste. However, more testing is needed in order to set the optimal parameters of the process.

The aim of this study was to investigate the influence of chemical leaching on permeability and Cd removal from fine-grained polluted soils. Column leaching experiments were conducted using two types of soils (i.e., artificially Cd-polluted loam and historically polluted silty loam). Chemical agents of CaCl₂, FeCl₃, citric acid, EDTA, rhamnolipid, and deionized water were used to leach Cd from the soils. Results showed that organic agents reduced permeability of both soils, and FeCl₃ reduced permeability of loam soil, compared with inorganic agents and deionized water. Entrapment and deposition of colloids generated from the organic agents and FeCl₃ treatments reduced the soil permeability. The peak Cd effluence from the artificially polluted loam columns was retarded. For the artificially polluted soils treated with EDTA and the historically polluted soils with FeCl₃, Cd precipitates were observed at the bottom after chemical leaching. When Cd was associated with large colloid particles, the reduction of soil permeability caused Cd accumulation in deeper soil. In addition, the slow process of disintegration of soil clay during chemical leaching might result in the retardation of peak Cd effluence. These results suggest the need for caution when using chemical-leaching agents for Cd removal in fine-grained soils.

Environmental contamination, especially due to the increasing use of pesticides, is suggested to be one out of six main reasons for the global amphibian decline. Adverse effects of glyphosate-based herbicides on amphibians have been already discussed in several studies with different conclusions, especially regarding sublethal effects at environmentally relevant concentrations. Therefore, we studied the acute toxic effects (mortality, growth, and morphological changes) of the commonly used glyphosate-based herbicide formulation Roundup® UltraMax on early aquatic developmental stages of two anuran species with different larval types (obligate vs. facultative filtrating suspension feeders), the African clawed frog (Xenopus laevis) and the Mediterranean painted frog (Discoglossus pictus). While X. laevis is an established anuran model organism in amphibian toxicological studies, we aim to establish D. pictus as another model for species with facultative filtrating larvae. A special focus of the present study lies on malformations in X. laevis embryos, which were investigated using histological preparations. In general, embryos and larvae of X. laevis reacted more sensitive concerning lethal effects compared to early developmental stages of D. pictus. It was suggested, that especially the different morphology of their filter apparatus and the higher volume of water pumped through the buccopharynx of X. laevis larvae lead to higher exposure to the formulation. The test substance induced similar lethal effects in D. pictus larvae as it does in the teleost standard test organism used in pesticide approval, the rainbow trout (Oncorhynchus mykiss), whereas embryos of both species are apparently more tolerant and, conversely, X. laevis larvae about two times more sensitive. In both species, early larvae always reacted significantly more sensitive than embryos. Exposure to the test substance increased malformation rates in embryos of both species in a concentration-dependent manner, but not at environmentally relevant concentrations. However, the assumed field safety, based on calculated surface water concentrations of the active ingredient (glyphosate), should be validated with realistic field data and buffer strips have to be urgently regarded to any aquatic amphibian habitat.

Commercial mixtures of chlorpyrifos and cypermethrin pesticides are widely used to enhance the toxic effects of cypermethrin on target insects. So, the purpose of the current study was to evaluate the individual and combined toxic effects of chlorpyrifos (CPF) and cypermethrin (CYP) on reproductive system of adult male albino rats. Forty adult male albino rats were randomized into main four groups: group I (control group) included 16 rats, subdivided into negative and positive control; group II (eight rats) received chlorpyrifos 6.75 mg/kg b.w./orally∕daily); group III (eight rats) (received cypermethrin 12.5 mg/kg b.w./orally∕daily); and group IV (eight rats) (received chlorpyrifos and cypermethrin at the same previously mentioned doses). All treatments were given by oral gavage for 12 weeks. We found that single CPF and CYP exposures significantly have adverse effects on reproductive function of adult male albino rats manifested by reduced testicular weight, decreased sperm count, motility and viability, significantly increased percent of morphologically abnormal spermatozoa, and significant increments in sperm DNA fragmentation index (DFI) with respect to control group. Furthermore, serum follicle stimulating hormone, luteinizing hormone, and testosterone levels were decreased significantly compared to control group. This was accompanied with histopathological changes in the testis of rats such as necrosis, degeneration, decreasing number of spermatogenic cells in some seminiferous tubules, edema, congested blood vessels, and exudate in interstitial tissue of the testis. Notably, all these changes were exaggerated in rats treated concomitantly with chlorpyrifos and cypermethrin rendering the mixture more toxic than the additive effects of each compound and causing greater damage on the reproductive system of male albino rats than the individual pesticides.

The production of table olives is a significant economic activity in Mediterranean countries. Table olive processing generates large volumes of rinsing water that are characterized by high organic matter and phenol contents. Due to these characteristics, a combination of more than one technology is imperative to ensure efficient treatment with low operational cost. Previously, biological filters were combined with electrooxidation to treat table olive washing water. Although this combination was successful in reducing pollutant loads, its cost could be further reduced. Constructed wetlands could be an eligible treatment method for integrated table olive washing water treatment as they have proved tolerant to high organic matter and phenol loads. Two pilot-scale horizontal subsurface constructed wetlands, one planted and one unplanted, were combined with a biological filter and electrooxidation over a boron-doped diamond anode to treat table olive washing water. In the biological filter inlet, chemical oxygen demand (COD) concentrations ranged from 5500 to 15,000 mg/L, while mean COD influent concentration in the constructed wetlands was 2800 mg/L. The wetlands proved to be an efficient intermediate treatment stage, since COD removal levels for the planted unit reached 99 % (mean 70 %), while the unplanted unit presented removal rates of around 65 %. Moreover, the concentration of phenols in the effluent was typically below 100 mg/L. The integrated trickling filter-constructed wetland-electrooxidation treatment system examined here could mineralize and decolorize table olive washing water and fully remove its phenolic content.

Pharmaceutical residues are not completely removed in wastewater treatment plants (WWTPs) becoming contaminants in aquatic ecosystems. Thereby, it is important to investigate their concentrations in the environment and the possible consequences of their occurrence, including for human health. Here, we briefly reviewed the paths of pharmaceuticals to reach the environment, their behavior and fate in the environment, and the possible consequences of their occurrence. Moreover, we synthetized all the studies about the detection of pharmaceuticals in Brazilian water bodies and the available ecotoxicological knowledge on their effects. In this study, when we compare the data found on these compounds worldwide, we observed that Brazilian surface waters present considerable concentrations of 17α-ethinylestradiol, 17β-estradiol, and caffeine. In general, concentrations found in aquatic systems worldwide seems to be low; however, ecotoxicological tests showed that even these low concentrations can cause sublethal effects in biota. The knowledge about the effects of continuous exposure and mixtures is sparse. In summary, new research is urgently required about the effects of these compounds in biota—including long-term exposition and mixture tests—and on specific technologies to remove these compounds in water bodies and WWTPs, besides the introduction of new policies for pharmaceutical use.

The toxic heavy metal cadmium (Cd) appears as one of the major global threats to human and animal health. Human being and aquatic life are exposed to Cd by breathing, eating, or drinking when industrial effluents released into environment. The study was aimed to identify cadmium-binding Lactobacillus strain to reduce its bioaccessibility in in vitro digestion model. In this context, forty-eight lactobacilli strains isolated and characterized from fermented dairy products and human origin were screened for their Cd biosorption potential using Flame Atomic Absorption Spectroscopy (FAAS). The present study revealed that Cd biosorption potential of 48 lactobacilli strains ranged from 1.0832 ± 0.012 to 3.562 ± 0.03 mg Cd g⁻¹ of cells from initial 10 mg L⁻¹ cadmium chloride (CdCl₂) aqueous solution. Lactobacillus plantarum strain HD 48 demonstrated highest biosorption of 3.562 ± 0.03 mg Cd g⁻¹ of cells. Lactobacilli-Cd complex stability indicated its strong stability as even after three washes with Milli-Q water metal desorption was nonsignificant (p < 0.05) and further studies to delineate the influence of Cd (100 mg L⁻¹ CdCl₂) on their growth. Moreover, these strains were able to reduce Cd bioaccessibility in the in vitro digestion model in the range of 24.71 to 41.62 %. Transmission electron microscopy (TEM) investigations on Cd bioadsorption also revealed its surface associated bioadsorption phenomenon. These findings depicted that probiotic strain L. plantarum HD 48 was found to be endowed with remarkable Cd biosorption ability as well as reduction in its bioaccessibility. These results suggest that probiotic strain L. plantarum HD 48 has immense potential to sequester Cd from aqueous solution which could be further explored as a potent source to diminish body Cd burden.

Rare earths (RE), chemically uniform group of elements due to similar physicochemical behavior, are termed as lanthanides. Natural occurrence depends on the geological circumstances and has been of long interest for geologist as tools for further scientific research into the region of ores, rocks, and oceanic water. The review paper mainly focuses to provide scientific literature about rare earth elements (REEs) with potential environmental and health effects in understanding the research. This is the initial review of RE speciation and bioavailability with current initiative toward development needs and research perceptive. In this paper, we have also discussed mineralogy, extraction, geochemistry, analytical methods of rare earth elements. In this study, REEs with their transformation and vertical distribution in different environments such as fresh and seawater, sediments, soil, weathering, transport, and solubility have been reported with most recent literature along key methods of findings. Speciation and bioavailability have been discussed in detail with special emphasis on soil, plant, and aquatic ecosystems and their impacts on the environment. This review shows that REE gained more importance in last few years due to their detrimental effects on living organisms, so their speciation, bioavailability, and composition are much more important to evaluate their health risks and are discussed thoroughly as well.